Venue: Flushing Meadows, New York Date: 31 August - 13 September
BBC coverage: Live text commentaries on the website from 1600 BST each day, regular updates on 5 live, full commentary on 5 live sports extra in week two, both finals on 5 live
Roddick is seeded to meet Djokovic in the quarter-finals
Fifth seed Andy Roddick maintained his good form as he swept past France's Marc Gicquel in the night session to reach the third round of the US Open.
The American won 6-1 6-4 6-4 in a match that finished after midnight local time on Arthur Ashe Stadium.
Roddick goes on to face 6ft 9ins American John Isner, who beat Turkey's Marsel Ilhan 6-3 6-4 7-6 (7-1)
Fourth seed Novak Djokovic earlier made smooth progress into round three with a straight-sets win over Carsten Ball.
The Serb, 22, came through 6-3 6-4 6-4 and will next face American qualifier Jesse Witten for a place in the last 16.
Djokovic could only break once in each set against the big-serving Australian and missed a further 13 break-point chances.
"It's always hard to predict what to expect in the match against a guy who you don't know basically," said Djokovic.
John's been playing a lot better and it's going to be a completely different match-up
"He was serving between 130, 140mph throughout the whole match. He was going for the serves. I knew he was going to try to be aggressive."
Djokovic added: "Physically I feel great. I feel ready. I feel confident on the court, mentally motivated and willing to do more. I just have a big desire to perform good and to win the matches."
James Blake, the 21st seed, enjoyed a dramatic 6-4 3-6 7-6 (8-6) 6-3 win over Olivier Rochus that saw the schedule pushed back on Arthur Ashe Stadium and the night session delayed.
As a result, Roddick did not begin his match until 10.20pm, but the 2003 champion had few problems despite some flamboyant hitting from Gicquel.
"Even in the second set when he got down, he started playing a little bit more aggressively and that was certainly the case in the last game," said Roddick.
"He came back and I was getting a little nervous there but I'm glad I was able to pull it out."
Looking ahead to his match with the 6ft 9ins Isner, Roddick added: "John's been playing a lot better and it's going to be a completely different match-up.
"I'm not going to be able to break as much as in these first couple of matches and it's going to come down to a couple of points here and there."
Two-time semi-finalist Nikolay Davydenko swept aside Jan Hernych 6-4 6-1 6-2 to reach the third round.
Spain's Fernando Verdasco, seeded 10th, also won easily, to set up a clash with in-form veteran Tommy Haas.
The 25-year-old - who won his first ATP Tour title in New Haven last week - triumphed 6-3 6-0 6-3 in less than 90 minutes against Florent Serra of France.
Germany's Haas, the 20th seed, had to work slightly harder, converting just two of 18 break points before eventually beating Robert Kendrick 6-4 6-4 7-6 (7-3).
The victory was Hass's 30th at Flushing Meadow and the 31-year-old says that he is enjoying his tennis as his career moves into its final years.
"Other aches and pains come along as you get older," said the German, who has had surgery on his shoulder three times.
"Anybody will tell you that. But it's still good enough for me to go out there and compete."
Robin Soderling, seeded 12th, was handed an easy passage into round three when his Spanish opponent Marcel Granollers was forced to retire in the third game of their match with a back injury.
Sam Querrey, the 22nd seed, also made progress thanks to a 7-5 6-7 (8-6) 6-4 6-4 win over Kevin Kim and will play Soderling next.
And another American, Witten, continued his unexpected run of wins by seeing off Argentina's Maximo Gonzalez 6-7 (7-3) 6-4 7-5 6-2.